[llvm-mca] Round UP when formatting Reciprocal Throughput (#159544)
Explicitly round up the reciprocal calculation,
so that .125 is displayed as 0.13 consistently across all hosts.
Fix buildbot failure
https://lab.llvm.org/buildbot/#/builders/193/builds/10666
since https://github.com/llvm/llvm-project/pull/154495